Rotary cylinder compressor



c. G. JARME ROTARY CYLINDER COMPRESSOR Aug. 16, 1949.

Filed Sept 29, 1947 -fzg 5,

Patented Aug. 16,1949 1 a 2,479,117

' female thread .01 the cylinder.- Preferably, the bers are obtained. both outside and inside'the pistonrotates atthe same orsubstantially same threaded piston 3 with a resulting redoubling of ically and, as viewed inan axial section, step-like threads packingstrips I8 and I9 are placed in machine. 15 strips may be of the shape shown in Fig. 3. To

' s 2,479,11'7 I ROTABYCYLINDER COMPRESSOR V v Carl Gunnar Jarme, Finspong, Sweden I Application September 29, 1947, Serial No.776,654'

' In Sweden October 4, 1946 a 5 Claims. (01.23 440) 1 4 I I 1 I -2 The present invention relates to rotary comthat the screw-threaded piston 18 ishollow and pressors of the type comprising a rotatable cylin- .on.;its .inside provided with a female thread I der having a female thread and a screw-threaded of the same shape as its screw-thread. Said'fepiston eccentrically mounted in said cylinder so male thread I5 is engaged by a screw-thread I6 as to form a continuous crescent-shaped working 5 formed on an inner member I! rigidly connected chamber between its own screw-thread and the 1 to the cylinder I.. By this means working chamangular velocity asthe cylinder. v the capacity of the compresson. The working The invention is characterized, chiefly, by the medium enters through port'5 and is discharged fact that the threads of the cylinder and piston after compression through the channels l3 and I4. comprise one sided square threads tapering con- In order to obtain a tight sealing between the from the suction side to the pressure side of the grooves formed in the'respective members. Such In the accompanying drawing Fig. 1 is an axial manufacture such a strip a spiral slot is cut in a section of an embodiment of the invention, Fig. 2 sheet metal plate. The inner end of the spiral is an axial section of another embodiment, and strip thus obtained may be provided with a bush- Figs. 3-5 are detail views. ing 29 to receive a helical spring 2| the object of With reference to Fig. 1 the numeral I desig- 20 which is to force the tightening strip against the nates the cylinder and 2 is a motor shaft formed respective tightening surface. In Fig. 4 is shown integrally with or rigidly connected to the cylina section on the line 22 of Fig. 3 taken on a someder I. Formed on the external surface of the what larger scale.

cylinder are cooling ribs 3. The inside surface Fig. 5 is an axial section of a portion of an exof the cylinder is shaped as a female thread 4, ternally and internally threaded piston compristapering conically and, as viewed in an axial secing two resilient members 23 and 24 engaging tion, step-like from the suction side of the cylineach other to secure a tight sealing. Each of said der, as represented by an intake port 5 formed in members comprises an angle bar bent to a spiral a cover 6 at one end of the cylinder, towards the shape in hot state.

pressure side as represented by a pressure cham- By introducing a gas in the opposite direction ber 7 adjacent the other end of the cyinder. to that of the medium above supposed and allow- Lccated in the cylinder I is a piston 8 the thread ing it to expand in the machine a motor will be of which is similar in shape to that of the'cylinobtained.

der. The piston is mounted eccentrically with 7 What I claim is:

relaton to the cylinder I by means of a journal 9 5 1. In a machine of the class specified the comengaging a bushing III which is attached to a bination of a first rotatable member having a stationary casing II by means of a screw I2. As cavity bounded by radial and peripheral helical shown, the said two coengaging threads are in surfaces in echelon formation and of diameters contact with each other only at their uppermost gradually reduced towards the inner end of the points thereby giving rise to a. set of crescent- 40 cavity so as to form a one-sided square helical shaped working chambers between the cylinder female thread .of correspondingly reduced diamand the piston. When the cylinder I rotates the eter, a second rotatable member eccentrically screw-threaded piston is also caused to rotate. mounted in said first-mentioned member, said In this rotation the crescent working chambers second member having a similar one-sided square which are closed at their uppermost points, as helical screw thread on its peripheral surface for already stated. will move towards the pressure engaging the female thread of said first member,

chamber I while being subjected to a continuous the dimensions of said threads being so proporreduction of their volumes, thereby effecting a tioned as to give rise to the formation of a set corresponding compression of the medium conof crescent-shaped fluid receiving working tained therein. The compressed medium is dischambers of gradually varying capacity, and charged from the pressure chamber 7 through means for effecting a tight sealing between co- 9. channel I3 extending through the journal 9 and engaging surfaces of said threads.

a channel I4 formed in the stationary casing I I. 1 2. In a machine of the'class specified the com- The embodiment shown in Fig. 2 differs from bination of a first rotatable member having a that above described substantially by the feature cavity bounded by radial and peripheral helical surfaces in echelon formation and of diameters gradually reduced towards the inner end of the cavity so as to form a one-sided square helical female thread of correspondingly reduced diameter, a second hollow rotatable member eccentrically mounted in said first-mentioned member, said second member having one-sided square threads formed by radial and axial helical surfaces of gradually-varying diameters both og its external "and internal surfaces-;saidexternal thread being arranged to engage the female thread of the said first member for providing therein a set of crescent-shaped; worhigig phambers of gradually decreased capacity, a third rotatable member rigidly connected withsald first rotatable memben said memben one-sided square helical screw th earl o .g ually varying diameter for e a i t e n er thread of said second member, and packingstrips inserted between the-threads of the second member'andthose ofhthe firstandthirdsmembers.

3. H In a: machine of Y the classspecified the combination of 'a --first. rotatable member having a cavity bounded by radial: and peripheral helical suriiaces in echelon-formation and of diameters gradually reduced .towards the .innenend: oft-the wcavity sovas to :iorm acne-sided square helical :Eemalenthreadof 1correspondinglywreducedadiameter, a secondrotatable; member eceentrically mounted is inzsaid: first-mentioned imember -r-sald second member having a similar one sided-square whelical:-screw thread i on. its 4 peripheral surface ior engaglng thew-female-thread of said first-member, =the dimensions" oh saidi threadsisbeing so proportioned as to give rise to the formation of a set .of crescent-shaped fluid receiving working ichambers of gradually varying capacity, and flexible packing strips provided between coengaging the coengaging threads.

claimed in claim 1, and

1a internal iemal: thread the further 'feature that the second member comprises two resilient members.

a, a-rets machine and in which the second as claimed in claim 1, member is hollow and -15 -provided with an external screw-thread and an ternal terr alethread, the further feature that 9nd member comprises bars one of which surrounds the other.

two helically bent QARL GUNNAR J ARME.

r; EQEEQBEHQES 'aQ 'JEE 3.1 1119 @QHQWiIlg references are of record in th 96 t is patent:

*f Nu-mber 4 132953968 r France .=.1une .1; 51911 the threads for efiecting a 

